1. Field of the Invention
The present invention relates to a method for recording onto a recording medium such as a high-density rewritable optical disk a multi-channel broadcast stream in which data streams belonging to a plurality of channels are multiplexed, and for managing the recorded multi-channel stream.
2. Description of the Related Art
The standardization of a high-capacity rewritable optical disk, so called ‘Blu-ray Disk Rewritable’ (abbreviated ‘BD-RW’), is in rapid progress so that various products related with a BD-RW will be developed and commercialized in the near future.
FIG. 1 is a simplified block diagram of an optical disk device, which may be a VDR (Video Disk Recorder), capable of recording and reproducing signals to/from a recording medium such as a BD-RW.
The disk device of FIG. 1 comprises an optical pickup 2 for reading signals recorded on a recording medium 1 such as a BD-RW and for writing data stream processed from input signals; a VDR system 3 for restoring digital data by processing the read signals from the optical pickup 2 and for converting the input signals to data stream whose format is suitable for recording;
and an encoder 4 for encoding analog input to deliver to the VDR system 3.
The VDR system 3 of the disk device configured as FIG. 1 records an input data stream onto the placed BD-RW 1. The input data stream may be a digital TV broadcast stream provided through a tuner or be a digital data stream provided from a personal computer (PC) through a digital interface such as IEEE1394 standard.
The digital TV broadcast stream is classified into two types, one for an open broadcast stream and the other for a private broadcast stream. The open broadcast stream, which may be major TV broadcast stream formats in many countries, means that its stream syntax has been opened. Therefore, the syntax of open broadcast stream can be analyzed by a VDR system of any disk device. The well-known ATSC DTV stream in USA, DVB stream in Europe, and ARIB IDSV stream in Japan pertain to the open broadcast stream.
On the other hand, the private broadcast stream means a broadcast stream of which syntax is difficult for a DVR system of an ordinary optical device to analyze. The private broadcast stream is generally broadcasted through a cable or a satellite.
The digital TV broadcast stream may be a broadcast stream that contains program streams of a plurality of logical channels (subchannels). For instance, the ATSC D-TV format standardized in USA can accommodate a single HD-grade program stream or plural SD-grade program streams in a single physical (RF) channel, thus, a digital TV broadcast stream in which a plurality of SD-grade program streams are multiplexed is called a multi-channel broadcast stream.
Thus, the disk device must be able to record different types of data stream, namely, an open broadcast stream, a private broadcast stream, and a multi-channel broadcast stream on a BD-RW.
When the disk device records a multi-channel broadcast stream onto a BD-RW at user's request, it is preferable to write management information for individually accessing each subchannel data stream and trick play. However, what management information to create and how to write it have not been resolved yet.